JSON-delta is a multi-language software suite for computing deltas between JSON-serialized data structures and applying those deltas as patches. It enables separate programs at either end of a
communications channel (e.g. client and server over HTTP, or two processes talking to one another using bidirectional IPC) to manipulate a data structure while minimizing communications overhead. Robust reference implementations are available in Python and Javascript. Work is ongoing on other implementations, including Racket and Perl.

hg-diff is a simple GUI program to browse mercurial revisions. It is used to display a summary of all changes between two revisions and to display a graphical comparison of the two versions of each changed file.

owl2vcs is a set of tools designed to facilitate version control of OWL 2 ontologies using version control systems. It contains a commandline diff tool for OWL 2 ontologies integrated with Git and Mercurial. It detects axioms additions and removals, imports' additions and removals, ontology annotations' additions and removals, prefix additions, removals, modifications, and renames, ontology IRI and version IRI changes, and ontology format changes. It supports RDF/XML, OWL/XML, OWL Functional Syntax, Manchester OWL Syntax, and Turtle. It provides a changeset serializer and parser, two formats of changes, compact (like OWL Functional Syntax) and indented (the same, but more readable, using indents instead of parentheses), and four formats of IRIs: Simple, QName, Full, and Label.

SafePatch lets you edit program files and track those changes creating "patches" which can later be reverted or reused in a different setup. It's written in PHP, but can patch non-PHP applications because no integration into their source code is required. A bundled Control Panel allows easy tracking, installing, reverting, and diffing of available patches. SafePatch has an intuitive text patch file syntax which is uniform for text and binary files and independent of the engine being patched, has default support for VQMod .xml patches and FluxBB README mods, is written in OOP and uses events (and thus is easily extensible), and doesn't need a database.

This program is especially useful when the main difference between the two LaTeX files is in permutation of sections, moved equations, etc. Given 2 LaTeX files, it prepares 2 annotated LaTeX files showing which equations of the 1st file are identical, or close, or similar, to which equations of the 2nd file. It does the same with the pieces of text. It also saves the snippets of text and equations from each text into separate files in 2 new folders, allowing the user to see the difference using a diff program.

sqlite dbdiff is a simple command line program for showing the differences between SQLite databases. It shows the differences between table names, schema, row counts, and data. The current implementation uses a symmetric difference; more modes may be added in the future.

DiffKit is an application and a framework, for comparing two tables of data, field-by-field. The tables can come from any of a number of sources, such as an RDBMS or CSV file, and DiffKit is able to mix different kinds of sources in the same diff operation. It is like the Unix diff utility, but for tables instead of lines of text. Diffs can be reported at both the row and field level, and the user can configure what to compare, how to compare it, what to ignore). DiffKit is highly customizable with respect to the sources of tabular data, the details of the comparison, and the characteristics of the output (diff report).

Replo is a cross-platform utility for performing syntactically-aware diff, find, and replace operations. It is similar to IntelliJ's "structural find and replace" feature but allows for configurable grammars. With Replo, users can compare, detect, and replace idiomatic structures without worrying about irrelevant stylistic inconsistencies. Common grammars (e.g. C, C++, C#, Java, Ruby) are provided, but users can also leverage ANTLR to define their own.